The following relates generally to wireless communication, and more specifically to techniques for low latency communications in wireless communications systems.
A wireless communication network may include a number of base stations that can support communication for a number of mobile devices. A mobile device may communicate with a base station via downlink (DL) and uplink (UL) transmissions. The downlink (or forward link) refers to the communication link from the base station, such as an enhanced NodeB (eNB), to a mobile device, also referred to as a user equipment (UE). The uplink (or reverse link) refers to the communication link from the mobile device to the base station.
Multiple access technologies may use Frequency Division Duplexing (FDD) or Time Division Duplexing (TDD) to provide uplink and downlink communications over one or more carriers. TDD operation may provide relatively flexible deployments without requiring paired spectrum resources. TDD formats include transmission of frames of data, each including a number of different subframes in which different subframes may be uplink or downlink subframes. In systems that operate using TDD, different formats may be used in which uplink and downlink communications may be asymmetric. FDD operation utilizes different carriers for concurrent uplink and downlink communications.
In some wireless communication networks, base stations and UEs may support operation on multiple carriers, which may be referred to as carrier aggregation. Carrier aggregation may be used to increase throughput between a base station supporting multiple component carriers and a mobile device, and mobile devices may be configured to communicate using multiple component carriers associated with multiple base stations.
In some instances, a mobile device may need to initiate communications with a base station, or the base station may need to initiate communications with the mobile device. In many existing deployments the time period between a trigger and the initiation of data communications after the trigger may be on the range of several milliseconds. In certain situations, it may be desirable to have a reduced latency between a trigger and initiation of communications.